On Tue, Feb 23, 2021 at 12:11:30PM +0100, Borislav Petkov wrote: > From: Borislav Petkov <b...@suse.de> > > vc_decode_insn() calls copy_from_kernel_nofault() by way of > vc_fetch_insn_kernel() to fetch 15 bytes max of opcodes to decode. > > copy_from_kernel_nofault() returns negative on error and 0 on success. > The error case is handled by returning ES_EXCEPTION. > > In the success case, the ret variable which contains the return value is > 0 so there's no need to subtract it from MAX_INSN_SIZE when initializing > the insn buffer for further decoding. Remove it. > > No functional changes. > > Signed-off-by: Borislav Petkov <b...@suse.de>
Reviewed-by: Joerg Roedel <jroe...@suse.de> > --- > arch/x86/kernel/sev-es.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c > index 84c1821819af..1e78f4bd7bf2 100644 > --- a/arch/x86/kernel/sev-es.c > +++ b/arch/x86/kernel/sev-es.c > @@ -267,7 +267,7 @@ static enum es_result vc_decode_insn(struct es_em_ctxt > *ctxt) > return ES_EXCEPTION; > } > > - insn_init(&ctxt->insn, buffer, MAX_INSN_SIZE - res, 1); > + insn_init(&ctxt->insn, buffer, MAX_INSN_SIZE, 1); > insn_get_length(&ctxt->insn); > } > > -- > 2.29.2
